From Bulbapedia, the community-driven Pokémon encyclopedia.
A Club is a place in the video game version of the Pokémon Trading Card Game. It is similar to a Gym in a way that there are eight Clubs and they give out Master Medals after defeating the Club Master, just like how Gyms give out Badges after defeating the Gym Leader. One difference is that the player can challenge any club in any order.
The eight clubs are: